Mass Effect 2 is the sequel to the hit 2007 title, Mass Effect. The game is developed by Bioware for both the XBOX 360 and Microsoft Windows platforms. Realeased in January 2010, Mass Effect 2 will follow Commander Shepard and he/she once again battles for the survival of the galaxy.

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The game begins two months after the Reaper invasion on the Citadel. After saving the Galaxy from certain doom, Depending on your choice at the end of ME1 the old or newly formed Citadel Council send Commander Shepard to hunt and destroy any remaining Geth forces in the Galaxy.

During a routine mission to find Geth, the SSV Normandy comes under attack from an unknown enemy ship. The majority of the crew are safely evacuated after the Normandy is hit by a powerful laser blast (Navigator Pressley is the only major casualty). As the ship begins to fall apart, Shepard stays behind to rescue the Normandy pilot, Joker. Shepard manages to get Joker to an escape pod in time, but then the Normandy is hit by another blast from the enemy ship. This knocks Shepard away from the escape pod and sends him into space just before the Normandy is destroyed. Oxygen then begins to leak from Shepard's space suit, suffocating him before his life-less body plunges down to the planet below.

What remained of Shepard's body was collected by the pro-human organisation Cerberus. His body was used as part of the Lazarus Project, which looked to remake and revive Commander Shepard. Using both organic and synthetic parts, Commander Shepard was re-built after two years of work. The project was funded by someone known only as the Illusive Man, one of the top men in Cerburus. He informs you that the enemy who attacked the Normandy two years ago were the Collectors and since the attack they have been abducting entire Human colonies through-out the Terminus Systems. Shepard agrees to work with Cerburus to help finding out the reason behind the abductions. To help him in his mission, he is reunited with Joker and given a new star ship which he christened the Normandy SR-2. Cerberus also sent two of their top Operatives, Miranda Lawson and Jacob Taylor to assist Shepard in his mission.

In order to prepare himself for a battle against the Collectors, Shepard was asked to assemble a team from the very best the Galaxy had to offer, to accompany him on what was believed to be a suicide mission through the Omega 4 Relay.

Commander Shepard is given a list of 12 characters to recruit in order to complete his suicide mission (Zaeed Massani and Kasumi Goto are available through downloadable content). Each character is has a personal mission to complete in order to gain their loyalty. Having a characters loyalty will increase their chances on surviving the final mission.

All of you squad mates that survived in the orginal Mass Effect will also make an appearance if you load a game with a Mass Effect character. Some minor characters from the first game will also make an appearance depending on the choices you made.

Mass Effect 2 once again gives you the chance to create your perfect Shepard from scratch. You can choose to play as a male or female character. If you are not using a Mass Effect save file, you will be given the same three backgrounds from the first game to choose from. The options are a "colonist" (Living just outside of Earth's atmosphere in hostile environments), "earthborn" (You lived a rough chlidhood in the slums of Earth's cities), and "spacer" (You have lived and breathed aboard starships for your entire existance).
The same six classes are still available at the start of the game, each class has five unique powers and one bonus power to be unlocked. The classes are Soldier, Engineer, Adept, Infiltrator, Sentinel and Vanguard. The Soldier class is extremely skilled with weapons, the Engineer is good with Omni-tools and different tech abilities, and the Adept class is exceptional with biotic powers. The other three classes are combinations of the first three. The Sentinel is a combination of the Engineer and Adept classes, Infiltrators are a Soldier and Engineer combination, and the Vanguard is combination of the Soldier and Adept classes.

Using a Mass Effect save file will make you use the same gender and background that you had in the first game. However, you can choose to change Shepard's appearance and class.

Shepard and his squad are now able to regenerate health by staying on cover when badly injured. Medi-Gel is still part of the game, but it's now used as part of the Unity power to revive fall squad mates. You can carry up to 8 Medi packs at one time.

Mass Effect 2 allows you to target specific body parts for damage. Shoot someone in the legs will cause them to fall to the ground. Shooting enemies in the head will inflict extra damage.

The covering system has also been improved since the original Mass Effect. You can now enter cover manually instead of automatically covering when close to a wall. You also have the ability to jump over walls that are waist-high.

Unlike the first game which had dozens of weapons for each class, Mass Effect 2 only has around 3 or 4 different weapons to choose from each class. However the Normandy SR-2 is built with a research lab that allows you to add multiple upgrades to each weapon to improve it's ammo capacity, accuracy and power.

All weapons now require ammunition instead on cooling down automatically. All common weapons use Thermal Clips, which can be picked from the bodies of fallen enemies. Heavy Weapons require power cells which can usually be found in storage boxes on planets or by killing stronger enemies.

You can change the weapons in your inventory at the start of each mission after selecting you squad. You can also change them from the weapon lockers that can be found on certain planets or aboard the Normandy.

Armor is no longer limited to a full set. You can now choose specific pieces of armor different body parts. You can customise the helmet, chest, shoulders, arms and legs. Each piece of armor will give a bonus to things such as health, shields, damage, speed or ammo capacity. You can also full customize you armor with different colors, patterns and shininess. Your appearance aboard the Normandy can also be changed.

Mass Effect 2 allows you import a completed save file from the original game. This will carry over many of the important decisions you made in Mass Effect and improve the story for your own personal Commander Shepard. Key decisions that are transferred include saving Ashley or Kaidan, letting Wrex live or die and letting the Citadel Council live or die.

None of your experience points or abilities will be crossed over. This is because of major changes to leveling and powers. You also have the option to edit your appearance and class, however you background and psychological profile cannot be changed.

Certain accomplishments in Mass Effect will result in a bonus for your character in Mass Effect 2. Things such as reaching level 60, gaining the 'Rich' achievement or collecting all the minerals will give you a better head start going into Mass Effect 2.

Starting Mass Effect 2 without a Mass Effect save file will result in certain decisions being made by default. The original Council will be dead, Wrex will be dead, and the fate or Ashley or Kaiden will be judged by you gender (Kaiden survives if you're female, Ashley if you're male). Also none of the minor characters will make an appearance, except for Nassana Dantius and Harkin as they are tied to the storyline.